Someone saying that a mirror is swapped left and right is because they rotated themselves 180 degrees about the vertical axis to face the vertically aligned mir

Someone saying that a mirror is swapped left and right is because they rotated themselves 180 degrees about the vertical axis to face the vertically aligned mirror. If they used a horizontal axis instead, they would have swapped top and bottom. And if the mirror is horizontally mounted on the floor, anything goes. You'd probably say it swaps up and down, which is front and back from the mirror's point of view.